Method for manufacturing bleached wood powder and papers

ABSTRACT

The present invention relates to paper that is produced by mixing bleached wood powder with natural wood pulp, thereby improving the dewaterability while reducing the amount of pulp used such that inexpensive and high-quality paper is provided. The wood material is subjected to a process in which it is milled and dried and is then sorted to smaller than a predetermined size and cleaned, the cleaned wood powder is bleached by being stirred for a predetermined time after having been introduced together with a bleaching agent, and the wood powder resulting from the bleaching is subjected to grinding processing and to a sorting and cleaning process, thereby producing bleached wood powder, and paper is produced by mixing from 5 to 20% by weight of the bleached wood powder with from 80 to 95% by weight of natural wood pulp and then subjecting the mixture to a paper-making process.

TECHNICAL FIELD

The present invention relates to bleached wood power, a method of manufacturing the bleached wood power, paper using the bleached wood power, and a method of manufacturing the paper, which can improve dewaterability, reduce the amount of pulp used, and provide cheap and high-quality paper by manufacturing paper by mixing bleached wood powder with natural wood pulp.

BACKGROUND ART

In general, paper is manufactured using natural wood pulp or manufactured by a mixture of regenerated wood pulp. Various types of materials, such as wood, Chinese yam, the paper mulberry, chaff, sugar cane, and a papyrus, are used as natural wood pulp.

In general, paper is manufactured in a paper lamination form having several layers due to the efficiency of raw materials used and the dewaterability of a sheet forming process, and materials used in the paper manufacture are basically divided into natural wood pulp and regenerated wood pulp.

Recycled wood pulp deteriorates dewaterability and reduces the bulk and strength of paper because it has higher micro powder and ash content than natural wood pulp. In particular, a reduction of the bulk has a bad influence on a primary cost because it increases the use of wood pulp in a paper manufacture process. In the case of regenerated pulp, dry energy is increased because an ability to contain water is increased according to an increased number of recycling.

If the bulk of paper manufacture is increased, the amount of regenerated wood pulp used can be reduced and dry energy can be reduced. Accordingly, in a prior art, paper is manufactured by mixing the paper with regenerated wood pulp using wood powder for improving the bulk of paper manufacture in order to improve the bulk of paper manufacture by reducing the amount of wood pulp used, as disclosed in Korean Patent Registration No. 10-0898383.

However, wood materials are prepared, wood powder grinded by a grinder is sorted and selected, and the sorted and selected wood powder is used as the wood powder used in the above patent. In particular, the wood powder used in the above patent is not mixed with natural wood pulp, but is mixed with regenerated wood pulp. The wood powder is not widely used in white paper, and it increases the manufacture cost of paper because it does not reduce the amount of natural wood pulp more expensive than regenerated wood pulp.

Technical Problem

The present invention solves problems in that the amount of natural wood pulp used is not reduced because wood powder is used in regenerated wood pulp when using the wood powder in order to improve a bulk in manufacturing paper and that it is difficult to be used to manufacture white paper because not-bleached wood powder is used.

Technical Solution

A method of manufacturing bleached wood power in accordance with an embodiment of the present invention includes S10: a wood pulp dry step of performing a process of producing wood materials into wood pulp by grinding the wood materials using a grinder and drying the wood pulp in such a way as to have moisture content 1˜2 wt %; S20: a wood powder sorting and picking step of performing a process of sorting the wood pulp, dried in the wood pulp dry step, into wood powder having a length of a fiber of 0.15 mm and picking the wood powder; S30: a wood powder bleaching step of performing a process of inputting the wood powder, sorted and picked in the wood powder sorting and picking step, to bleaching equipment, adding a mixture of an H₂O₂ (hydrogen peroxide) aqueous solution and salt water to the bleaching equipment after a lapse of 5 minutes, driving the bleaching equipment so that the mixture and the wood powder are stirred and the wood powder is bleached for 40 minutes; S40: a bleached wood power dry step of drying the bleached wood power by supplying steam after bleaching the wood power in the wood powder bleaching step; and S50: a bleached wood power sorting and picking step of sorting and picking the bleached wood power dried in the bleached wood power dry step.

Furthermore, in a method of manufacturing paper using the bleached wood power in accordance with an embodiment of the present invention, paper is manufactured by mixing the manufactured bleached wood power of 5˜20 wt % with natural wood pulp of 80˜95 wt % and inputting the mixture to a sheet forming machine.

Advantageous Effects

The present invention is advantageous in that it can improve dewaterability and reduce energy because paper is manufactured by preparing wood powder, bleaching the wood powder, and mixing the bleached wood power with natural wood pulp in manufacturing paper by mixing regenerated wood pulp with the natural wood pulp and it can significantly reduce the amount of natural wood pulp used and the present invention is widely used to manufacture white paper because the bleached wood power is mixed with the natural wood pulp.

Furthermore, in accordance with the paper and the method of manufacturing the paper according to embodiments of the present invention, paper is manufactured by performing a process of grinding and drying wood materials, sorting the dried wood materials in a specific size or lower, and picking the sorted wood materials, inputting the picked wood powder and a bleaching agent, stirring the wood powder and the bleaching agent for a specific time so that the wood powder is bleached, and performing grinding, sorting, and picking processes on the bleached powder, thereby obtaining bleached wood powder, wherein bleached wood powder of 5 to 20 wt % is mixed with natural wood pulp of 80 to 95 wt %. Accordingly, the present invention is advantageous in that it is widely used to manufacture white paper because already bleached wood power is used and the amount of natural wood pulp used is reduced because of the improvement of a bulk.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flowchart illustrating the manufacture of paper according to the present invention, and

FIG. 2 is a flowchart showing the steps of a method of manufacturing bleached wood power in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION

A preferred embodiment of the present invention is described in more detail with reference to the accompanying drawings.

Embodiment

In the present invention, in paper manufacture, wood powder is bleached and then mixed with natural wood pulp instead of using a method of mixing the wood powder with regenerated wood pulp. Accordingly, the use of natural wood pulp can be reduced, and dewaterability can be increased and energy can be reduced due to an improved bulk.

A process of bleaching wood powder and a process of manufacturing paper using the bleached wood power in accordance with the present invention are described.

First, a method of manufacturing bleached wood power in accordance with an embodiment of the present invention is described step by step with reference to FIG. 2.

FIG. 2 is a flowchart showing the steps of a method of manufacturing bleached wood power in accordance with an embodiment of the present invention.

Step S10: wood materials are grinded into wood pulp using a grinder and the grinded wood pulp is dried so that the wood pulp maintains moisture content of 1˜2 wt %.

Step S20: wood powder having a length of a fiber of 0.15 mm or lower is picked and sorted from the dried wood pulp.

Step S30: the wood powder sorted and picked in the wood powder sorting and picking step is inputted to bleaching equipment. After a lapse of 5 minutes, a mixture of an H₂O₂ (hydrogen peroxide) aqueous solution and salt water is added to the wood powder. A process of driving the bleaching equipment and stirring and bleaching the wood powder for 40 minutes (i.e., a wood powder bleaching step) is performed. Here, the stirring time can be controlled depending on the degree of the mixture of the H₂O₂ (hydrogen peroxide) aqueous solution and the amount of salt water. Furthermore, when about 40˜70 minutes elapse after water was inputted to the wood powder, moisture is sufficiently penetrated into the wood powder. The results of experiments performed by the inventor of the present invention showed that about 50 minutes are appropriate. Here, temperature within a stirrer (not shown) for stirring the wood powder is maintained to a temperature range of 60˜80° C.

Step S40: after the wood powder is bleached in the wood powder bleaching step, the wood powder is dried by supplying steam.

Step S50: in the step of sorting and picking the bleached wood power dried in the bleached wood power dry step, the bleached wood power dried in the bleached wood power dry step is grinded and processed, thereby manufacturing the bleached wood power used to manufacture paper through the sorting and refining process.

The bleached wood power according to the construction of the present invention can be manufactured as described above.

Meanwhile, a step of manufacturing paper using the bleached wood power manufactured according to an embodiment of the present invention is described with reference to FIG. 1.

FIG. 1. is a flowchart illustrating the manufacture of paper according to the present invention.

First, the bleached wood power manufacturing according to the present invention is inputted (10), the bleached wood power of 5˜20 wt % and the natural wood pulp of 80˜95 wt % are mixed and then inputted to a sheet forming machine, thereby manufacturing paper using a common method.

That is, in the present invention, paper is manufactured by mixing the bleached wood power having a specific amount with natural wood pulp without using only natural wood pulp. Thus, the amount of natural wood pulp used can be reduced because the bulk of bleached wood power is improved, and energy according to paper manufacture can be reduced due to improved dewaterability.

Furthermore, unlike in an existing method of using wood powder without change, in the present invention, wood powder is bleached and used. Therefore, the present invention can be widely used to manufacture white paper in addition to the above advantages because.

A process of manufacturing the bleached wood power according to the present invention is described in detail, and a method of manufacturing paper using the bleached wood power is described in detail.

In the present invention, wood materials used to manufacture paper are prepared, and the prepared wood materials are inputted to a grinder so that the wood materials are grinded into wood pulp. The wood pulp grinded by the grinder is dried so that it maintains moisture content of 1˜2 wt % through a dry process.

That is, the wood materials are grinded into the wood pulp, and the grinded wood pulp is sufficiently dried so that the wood pulp maintains moisture content of 1˜2 wt %.

The wood pulp subjected to the grinding and dry process is sorted so that it has a length of a fiber of 0.15 mm or less and is then picked. In order for the wood pulp to have the above condition (i.e., the length of a fiber), a grinder is used, but wood powder exceeding the condition in the sorting process is moved to the grinder again and then subject to a grinding process so that the wood powder has the length of a fiber that can be used to manufacture paper.

The wood powder having the length of a fiber of 0.15 mm or lower through the sorting and picking process as described above, together with a certain amount of water, is inputted to bleaching equipment and remains intact for 5 minutes so that moisture can be sufficiently contained in the wood powder. The reason why moisture is contained in the wood powder is to perform bleaching smoothly.

Next, water is inputted along with the wood powder sorted and picked in the wood powder sorting and picking step. After a lapse of 5 minutes, when moisture is penetrated into the wood powder, a mixture of an H₂O₂ (hydrogen peroxide) aqueous solution and salt water is added to the bleaching equipment. Next, the hydrogen peroxide and the salt water are inputted to the bleaching equipment to which the wood powder soaked in water has been inputted as described above. The bleaching equipment is driven for 40 minutes so that stirring is performed so that the wood powder is bleached.

Furthermore, temperature within the stirrer (not shown) for stirring the wood powder and the wood powder maintains a temperature range of 60˜80° C. In this case, there is an advantage in that a uniform stir effect can be obtained.

After the wood powder is bleached through the bleaching equipment as described above, steam is moved from the bleaching equipment to steam equipment so that the bleached wood power is dried by the steam. Here, the dry process is performed on the wood powder of 1 ton for about 1 hour.

The bleached wood power dried by the steam through the above-described dry process is subject to the grinding process again and the sorting and picking process, thereby manufacturing the bleached wood power used to manufacture paper.

The bleached wood power manufactured using the above method is used to manufacture paper.

In order to manufacture paper, the bleached wood power of 5˜20 wt % and the natural wood pulp of 80˜95 wt % prepared as described above are mixed and then inputted to the sheet forming machine, thereby manufacturing paper. A process of manufacturing paper using the mixture of the bleached wood power and the natural wood pulp inputted to the sheet forming machine is common, and a detailed description thereof is omitted in the present invention.

That is, in the present invention, in manufacturing paper using natural wood pulp according to a common method, paper is manufactured using a mixture of natural wood pulp and bleached wood power. Accordingly, the amount of natural wood pulp used to manufacture white paper can be significantly reduced by the amount of inputted bleached wood power.

As described above, in the present invention, bleached wood power having a specific amount is mixed with natural wood pulp and used. Accordingly, there are advantages in that the use of natural wood pulp can be reduced because the bulk of bleached wood power is improved and energy according to paper manufacture can be reduced because dewaterability is improved. 

What is claimed is:
 1. A method of manufacturing bleached wood power, comprising: a wood pulp dry step of performing a process of producing wood materials into wood pulp by grinding the wood materials using a grinder and drying the wood pulp in such a way as to have moisture content 1˜2 wt %; a wood powder sorting and picking step of performing a process of sorting the wood pulp, dried in the wood pulp dry step, into wood powder having a length of a fiber of 0.15 mm and picking the wood powder; a wood powder bleaching step of performing a process of inputting the wood powder, sorted and picked in the wood powder sorting and picking step, to bleaching equipment, adding a mixture of an H₂O₂ (hydrogen peroxide) aqueous solution and salt water to the bleaching equipment after a lapse of 5 minutes, driving the bleaching equipment so that the mixture and the wood powder are stirred and the wood powder is bleached for 40 minutes; a bleached wood power dry step of drying the bleached wood power by supplying steam after bleaching the wood power in the wood powder bleaching step; and a bleached wood power sorting and picking step of sorting and picking the bleached wood power dried in the bleached wood power dry step.
 2. Paper manufactured using the bleached wood power manufactured according to a method of claim
 1. 3. The method according to claim 1, wherein paper is manufactured by mixing the manufactured bleached wood power of 5˜20 wt % with natural wood pulp of 80˜95 wt % and inputting the mixture to a sheet forming machine.
 4. Bleached wood power manufactured according to a method of claim
 1. 